Ever wondered what’s that meter next to the speedometer that reads up to 7 or 8 and has a red line towards the end? It is the RPM meter that counts the revolutions per minute. It basically counts the revolutions that the crankshaft makes in one minute and displays them on your tachometer.
When you press the accelerator, the RPMs increase as the motion of the crankshaft also increases, and you get more torque. You would usually notice the RPM needle go high in lower gears and when you rev during idling.
If your car won’t accelerate but RPMs go up, there’s something wrong with one of the engine parts, or transmission fluid most probably. This could simply be a clogged air filter or a faulty sensor. This comprehensive guide shall explain the 7 most common reasons why your car won’t accelerate but RPMs go high, and how you can fix it.
7 Most Common Reasons Your Car Won’t Accelerate but RPMs Go Up
Your engine has a lot of different parts that work in harmony to generate power and send it to wheels, via transmission and axle shaft. If your RPMs are going but the car is not accelerating, you should suspect one of the following problems;
Low Transmission Oil
Just like engine oil, the transmission system also uses a lubricant for its moving parts and it is necessary for power delivery. If your car won’t accelerate but RPMs go up, it could be due to this common, yet harmless problem of low transmission oil.
If the gear oil level is low, the power will get transmitted only to the torque converter and not the engine, hence your car would limp and not respond to throttle input as it should. If you’re facing this issue, immediately check the transmission oil level.
Faulty Torque Converter
The torque converter is an essential part of cars equipped with auto transmission and its function is to convert mechanical power from the engine to hydraulic power and propel your car by moving the wheels.
If the torque converter has become faulty or damaged due to wear, your car won’t accelerate but the RPM gauge would act normally.
The throttle position sensor is a modulator that senses the pressure applied on the gas pedal and sends a signal to ECU. The ECU then directs other components like fuel pump, air intake and other parts to work more and generate adequate power.
If this sensor malfunctions, the ECU would not get the correct reading and the engine will not generate power despite the RPM meter working just fine.
Malfunctioning MAF Sensor
Mass Airflow Sensor is linked to the air intake of the car and sends signals to ECU regarding the airflow for combustion. If this sensor gets damaged, the ECU will get a false signal and it would think that there’s no air flowing in through the intake manifold. The engine would not respond to the gas pedal and yet the RPMs would go up as usual.
This is one of the difficult problems to locate and usually requires a thorough diagnosis by an expert technician.
Throttle Body Problems
The throttle body is found in almost all modern vehicles and its function is to respond to the throttle input and generate enough output. It is also linked to the fuel pump and air intake system and manages the air/fuel mixture infusion into the cylinders.
If the throttle body has not been serviced for a while or it has worn out over time due to rough usage, your engine wouldn’t respond optimally to the throttle inputs and your car won’t accelerate but RPMs go up.
An ECU is the mastermind of the car’s engine and controls all the sensors, inputs, and outputs. If the ECU has corrupted, got damaged, or has faulty calibrations, your car would start acting abnormally.
If your car won’t accelerate but RMPs go up, it could be due to a faulty ECU and all other parts might be working normally.
Damaged/Clogged Fuel Pump
No matter how hard you press the gas pedal or how quickly you shift the gears, if the fuel pump is not sending enough fuel to the combustion chamber, your engine would keep limping.
A fuel filter is amongst the most ignored parts of the car and is usually not given attention during routine maintenance. Simply getting your clogged fuel pump serviced could get rid of this issue.
What Can You Do if Your Car Won’t Accelerate but RPMS Go Up?
If your car isn’t responding when you floor the gas pedal but you notice the RPMs behaving normally, there is no need to panic. Here are a few steps you could follow to get to the root of the problem and get it fixed.
1. Park your car at a safe location and go through the owner’s manual to locate some of the important components, so you can check them.
2. Initially, you should check all the fluids, especially the transmission oil and engine oil.
3. Check the air filter for debris or dirt, and the MAF sensor for corrosion or damage.
4. If you have a portable OBD-II scanner, quickly scan the ECU for some probable error codes. If you get some, check the manual for interpretation and note down the issues.
5. There’s no need to go for complex repairs yourself as you could worsen the damage. Simply call recovery and towing service, and get your car taken to a nearby workshop for diagnosis and repair by an expert mechanic.
6. Get the faulty parts and sensors replaced, and have all the filters and fluid levels checked thoroughly.
A car is a complex piece of machinery that has an array of components working in harmony to ensure optimal functioning and output. Despite being sturdy and reliable, a car could malfunction any time due to a faulty component or sensor.
If your car won’t accelerate but RPMs go up, there are certain components that could be at fault. It is imperative to get your car checked promptly and have the problem fixed, to avoid any costly and time taking hassle in the future.